← 🔐 Cryptography

🔐 The One-Time Pad: The Only Provably Unbreakable Cipher

Ciphertext:
Key status:
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🔐 The One-Time Pad: The Only Provably Unbreakable Cipher

This simulator shows how a message is transformed into random-looking ciphertext by combining it with a key stream, and how reusing that key stream against a second message reveals recoverable patterns.

🔬 What It Demonstrates

This simulator shows how a message is transformed into random-looking ciphertext by combining it with a key stream, and how reusing that key stream against a second message reveals recoverable patterns.

🎮 How to Use

Enter a plaintext message and a key, encrypt it to see the resulting ciphertext, then try reusing the same key on a different message to observe how the perfect secrecy breaks down.

💡 Did You Know?

The Venona project ran for over 30 years, from 1943 to 1980, before US and UK cryptanalysts finished extracting what they could from reused Soviet one-time pad traffic.